.selector-wrapper {
  background-color: #f5f7fa;
  padding: 16px 0;
}
.selector {
  width: 1200px;
  margin: 0 auto;
}
.selector-item {
  padding: 8px 0;
}
.selector-item-title {
  display: inline-block;
  width: 82px;
  height: 28px;
  line-height: 28px;
  font-size: 14px;
  font-weight: 500;
  color: #14171a;
  margin-right: 24px;
}
.selector-item-txt {
  display: inline-block;
  height: 28px;
  line-height: 28px;
  min-width: 20px;
  border-radius: 8px;
  font-size: 14px;
  font-weight: 400;
  padding: 0 8px;
  color: #667280;
  cursor: pointer;
  -webkit-user-select: none;
  -moz-user-select: none;
  user-select: none;
  transition: color 0.3s, background-color 0.3s;
  margin-right: 24px;
}
.selector-item-txt.active,
.selector-item-txt:hover {
  background-color: rgba(32, 128, 247, 0.1);
  color: #2080f7;
}
.lesson-wrapper {
  background-color: #ffffff;
}
.lesson {
  width: 1200px;
  margin: 0 auto;
  padding: 32px 0;
}
.lesson-top {
  display: flex;
  justify-content: space-between;
}
.lesson-top-title {
  line-height: 24px;
  font-style: normal;
  font-weight: 600;
  font-size: 18px;
  color: #14171a;
}
.lesson-top-result {
  font-size: 16px;
  line-height: 22px;
  color: #667280;
}
.lesson-top-result em {
  font-style: normal;
  font-weight: 600;
  color: #14171a;
  font-size: 16px;
  line-height: 22px;
}
.lesson-sort {
  display: flex;
  align-items: center;
  height: 68px;
}
.lesson-sort span {
  margin-right: 28px;
  display: inline-block;
  height: 28px;
  line-height: 28px;
  min-width: 20px;
  border-radius: 8px;
  font-size: 14px;
  font-weight: 400;
  color: #667280;
  cursor: pointer;
  -webkit-user-select: none;
  -moz-user-select: none;
  user-select: none;
  transition: color 0.3s, background-color 0.3s;
  text-align: left;
}

.lesson-sort span.active,
.lesson-sort span:hover {
  color: #2080f7;
}
.lesson-list {
}
.lesson-item {
  display: inline-block;
  width: 277px;
  background: #fff;
  box-shadow: 0 4px 30px rgba(0, 80, 179, 0.08);
  border-radius: 8px;
  font-family: PingFang SC, sans-serif;
  outline: none;
  transition: box-shadow 0.3s;
  min-height: 290px;
  margin-bottom: 24px;
  margin-right: 24px;
  vertical-align: top;
}
.lesson-item:nth-child(4n) {
  margin-right: 0;
}
.lesson-item .imger {
  width: 100%;
  background-image: url("../img/p1.png");
  background-position: center;
  background-size: cover;
  height: 150px;
  border-top-left-radius: 6px;
  border-top-right-radius: 6px;
}
.lesson-item .content {
  background-color: #fff;
  padding: 8px 12px 16px;
  position: relative;
}
.lesson-item .content-title {
  min-height: 48px;
  margin-bottom: 8px;
  font-weight: 500;
  font-size: 16px;
  line-height: 24px;
  color: #3e454d;
  word-break: break-all;
  transition: color 0.3s;
  cursor: pointer;
}
.lesson-item .content-title:hover{
  color: #2080f7;
}
.content-tag {
  margin-bottom: 12px;
  min-height: 22px;
}
.content-tag span {
  display: inline-block;
  position: relative;
  margin-right: 4px;
  max-width: 100%;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  height: 22px;
  line-height: 22px;
  padding: 0 4px;
  background: #edeff2;
  border-radius: 4px;
  font-size: 12px;
  color: #667280;
}
.content-price {
}
.content-price span:first-child {
  margin-right: 6px;
  font-size: 16px;
  color: #ff7a38;
  line-height: 19px;
}
.content-price span:last-child {
  font-size: 14px;
  line-height: 20px;
  color: #a1a9b2;
}
.page {
  margin-top: 48px;
  margin-bottom: 68px;
  text-align: center;
}
.page span {
  display: inline-block;
  border: 1px solid #edeff2;
  background-color: #fff;
  border-radius: 6px;
  padding: 9px 0;
  margin-left: 4px;
  margin-right: 4px;
  min-width: 66px;
  height: auto;
  font-family: inherit;
  line-height: 1;
  cursor: pointer;
}
.page span:hover,.page span.active{
  background-color: #2080f7;
  color: #ffffff;
}

@media screen and (max-width: 768px) {
  .selector{
    width: 90%;
  }
  .lesson{
    width: 90%;
    font-size: 0;
  }
  .lesson-item{
    width: calc(50% - 10px);
    margin-right: 20px;
  }
  .lesson-item:nth-child(2n){
    margin-right: 0;
  }
  .selector-item-title{
    display: block;
    margin-bottom: 8px;
  }
  .selector-item-txt{
    margin-bottom: 6px;
  }
  .selector-wrapper{
    padding: 0;
  }
  .page{
    margin: 20px 0;
  }
  .page-item{
    margin-bottom: 6px;
  }
 }